Containers, and more specifically metallic beverage containers, are typically manufactured by interconnecting a beverage container end closure to the neck of a beverage container body. In some applications, an end closure may be interconnected on both a top side and a bottom side of a container body. More frequently, however, a beverage container end closure is interconnected on a top end of a beverage container body. Generally, the configuration of the container end closure may affect the level to which consumers, as well as bottlers, manufacturers, distributors, shippers, and retailers, are satisfied with the container. One factor believed to be of some importance to consumers is the pour characteristics of the container. In general, it is believed that consumers prefer to use containers capable of providing a relatively high pour rate. Additionally, it is believed consumers prefer containers that provide a smooth or substantially laminar pour, i.e., a pour which is not characterized by a series of surges or “glugging” which can cause splashing and/or can affect a beverage head, fizz or other carbonation or pressurization-related characteristics of the contents after pouring.
Conventional beverage container end closures generally have a single pour opening defined by a score line. The pour opening is generally designed for pouring the container contents, with little or no consideration given to inward air flow needed for the volume exchange that facilitates smooth and consistent pouring. Therefore, conventional beverage container end closures generally suffer from low, inconsistent, and/or uneven flow rates as the contents in the container are poured due to the fact that these end closures have only one opening area of a predetermined size.
There are several types of container end closures that have attempted to improve end closure pourability. One type is an end closure with a full aperture opening similar to a food can in which the entire end panel detaches from the can. Such fully detachable container end closures are not a good solution to the pourability problem because the fully detachable end frequently becomes litter when consumers do not properly dispose of the detached end.
Other container end closures attempt to improve pourability with a secondary vent aperture which is separate from the primary drinking opening. The separate vent aperture can generally be opened with a separate tool or by pressing a secondary scored area into the container. Examples are provided in U.S. Patent Application Publication Nos. 2011/0108552, 2011/0266281, 2012/0048870, 2012/0199586, 2012/0260613, 2013/0118133, and WIPO Patent Application Publication No. 2008/023983 which are incorporated herein by reference in their entireties. The separate vent apertures of these designs are generally smaller than the primary opening limiting the flow of air into the container through the vent, and therefore, the end closures described by these publications do not substantially improve pourability.
In addition, some separate vent apertures of the designs described by these publications require the use of a separate tool to open the vent aperture. Requiring a separate tool to open the vent aperture is inconvenient and requires the consumer to carry the tool to take advantage of any improved pour characteristics that may result from opening the separate vent aperture. Other examples of separate vent apertures of these designs are opened by aligning the tail or rear edge of the tab interconnected to the end closure with the vent aperture and then pressing the rear edge down onto the secondary score to sever the secondary score. The separate vent apertures designed to be opened in this manner can result in accidental opening of the vent aperture during shipment or storage if the tab or some other object presses against the secondary score.
Still another design which attempts to improve end closure pourability includes a secondary gate or tear panel which is pushed into the container after the primary pour opening is opened. An example of this type of secondary vent is provided in U.S. Pat. No. 5,555,992 which is incorporated herein by reference in its entirety. In this design, secondary scores connect the secondary gate to the primary pour opening. However, once the primary pour opening is opened, the end panel becomes weak and deforms easily. End closures of this design do not have a large enough range of motion to overcome the flexing of the end closure panel and are difficult to open. Thus, this is not an effective design to improve the pourability of an end closure.
Other end closure designs include a second opening connected to the pour opening. Some examples are provided in U.S. Pat. Nos. 3,762,597, 4,397,403, and 4,402,421 which are incorporated herein by reference in their entirety. End closures of these designs generally have a very narrow second opening which may not provide sufficient air flow into an interior of the container to improve flow rate of contents out of the container. In some cases, a lift ring used to open the pour opening is interconnected to the end closure over the pour opening and the lift ring must be pulled back to open the second opening before the product contained in the container can be consumed.
Yet other designs for end closures attempt to improve pourability with a vent created by extending the score line of the pour opening past a bending plane of the tab. This creates a small area of air flow back into the container. This is the least effective design for improving pourability because of the limitation in the size of the vent due to tab functionality. Examples of these designs are provided in U.S. Pat. Nos. 4,289,251, 6,079,583, 7,975,884, and U.S. Patent Application Publication No. 2012/0031056, which are incorporated herein by reference in their entireties.
These prior art designs fail to teach various novel features of the present invention. Furthermore, many previous attempts to improving pouring characteristics have involved major changes to the design of the container end closure, thus involving relatively high tooling or other equipment costs, design costs, testing costs and the like. Accordingly, there is an unmet need for a container end closure which improves pour rate, consistency, and smoothness of pour without requiring major changes to the design of the container or retooling during the manufacturing process.